Comment 33 for bug 157721

If one looks at the code from sun.applet.AppletViewerPanel.getWidth(AppletViewerPanel.java:134) it looks like this:
Which suggest that the browser(? or something else other than the appletviewer) has to modify the <param name="width" value="100%" /> and replace 100% with the current value of "100%".

E.g. <param name="width" value="100%" /> becomes (on the browser)
<param name="width" value="923" /> which is what the appletviewer receives.

So this seems to be some kind of integration problem.

/**
     * Get the width.
     */
    public int getWidth() {
        String w = getParameter("width");
        if (w != null) {
            return Integer.valueOf(w).intValue();
        }
        return 0;
    }